"Peter II (German: Nikolaus Friedrich Peter) (8 July 1827 – 13 June 1900) was the reigning Grand Duke of Oldenburg from 1853 to 1900. He claimed hereditary parts of Duchy of Holstein after the Second Schleswig War in 1864. After signing a treaty on 23 February 1867 in Kiel, he renounced his claims. But, he received the district of Ahrensbök, the Prussian parts of the former Principality of Lübeck (except the village of Travenhorst), and was given a million taler as compensation from Prussia. Thus the Grand Duchy of Oldenburg gained access to the Baltic Sea." - (en.wikipedia.org 30.01.2020)
